Automatic telephone system



Sept 23 19% 1,509,298

E. JACOBSEN AUTOMATI C TELEPHONE SYSTEM 2 Sheet: -Shee1 1 Original Fi ed Sept. 5, 1918 Sept. 23 1924.

. 1509.298 E. JACOBSEN AUTOMATIC TELEPHONE SYSTEM Filed Sept. 5. 1918 2 shots-sheet 2 All Patented Sept. 23, 192.4,

tree estates OEEMIL JACOBSEN; or PQBEQ wesnmc'ron, NEW yonnfessrenon ro AUTOMATIC ELEC- TRICGOMPAINY, or GHICAGOQ11ILLIINOIS, A oonronamron o 'ILLrNoIs.

AUTO'MATIGQTEIJEPHONE SYSTEM.

, Application filed September 5,;1916},,Seria1 No. 252,764.; itenewedliebr-uary,15-1324.

= To, a llytvipom, it may, concern:

Bent, known that ,L EMIL JAooBsE f-a 1 LGijllZ Gllof the United States of Arnerica, and

,and: State of new York, have invented certainj .new, and usefulalmprovernents in a Automatic Telephone; Systems,,of which the ,if ollowing is a specification.

by a ,subcriber, orl through the mediurn of an operator to establish connections. @More specifically, noyinvention-relates to ,an improvedvconnector switch of the type 1-1ayin g automatic. trunk selecting functions,

such, as is [used for conn e'ctingv with trunk Qu t-lines egite n dinglto private branch exchanges, (and:being com nonly known as a rotary conmeter; The, connector shown hereinMmay l lhe considered as, being an improvement on Ethe, connector. shown. in any. pending applicationSer. No. 174,013,,fi1ed June 11,1917. My ,improved connector is, arranged ,so, that the,..,test of the first contactassociated with a L I group, of trunklines extending to i a private H branch exchange determines. whether, or not cthe're isQan idle trunkin that group. Also I, when this (connector. isnsed by an operator rt establish 'a ,connectionto such a vgroup of trunk ,lines, the connector will stop on the first contact ,of' the elected group, it all "the trunks are busy, and give. the operator the in that group become, idle, the. connector [will ,operate, tbLseize. that idle, trunk. This and ,;]other, objects oflinyfl invention will be more jtullyedescribedl hereinafter.

. :In the,dnawingscornprising Figures 1 and I have shown a sub-station A, alineswitch C individual to the line of sub-stationA, a selector ,switch'D, accessible to the linegswitfch I Q and a vrotary. connectorlswitch E, accessible to the selector,swi;tcl1.D. Accessible to the .connector switch E, Lhave shotwn a .,group of trunk linesextendTing toj a branch e'x- 7 change. i

heferringto Figure 1, thesub-lstation A .inaybe o fany approved automatic type, Such for example asthesub stationshownin the ,British patenttoMartin #1 l19 of 1910. As represented, herein, itfcornprises, essentially, the receiver l1, transmitter 12, lswitchhook 5 13, ,ringer l, and, condenser l5. f Being :an

of trunk lines extending to,selectorswitchese selector switch, disclosed "in SI lLet'ters.

busylsignal'ythen,whengany one of the trunks a ,to Keith, Erickson and Erickson. The side bank level comprises, ten. contact .sets, in, which terminate ten. trunlrlines, which latter automatic sub-station, it; is also, provided with anpair of irnpulse springsulo and .17, l Q'Which be. controlled a impulse 'a, 17esident of PortNVashington, Nassau' Coun-r wheel through thegrnediuni .oi' afingerhole dial (not shown). "i a Theline conductors l8 andl9 0t the snbstation A extend to the main exchange, where I 1 they terminate .in .an individual A line switch My invention relates in general to, .im- ,plgoved circuits and apparatus forqnsenin.

- Ql11l ll9l1lfllzl telephone systems, in which a automatic.switchesare controlled either auto- ,tersfPatent #1,126,727, granted. February 2,1915, to Dietl. 1. Through thefinediiun'of .ithe lineswitch C, the lineof substation A when calling, isgiVenacceSstQ aplurality One oithe trunk lines'vtowhi'ch thelline switch Chas access, istshownextending to the first seIectOrMsWitcl D. The fselector switch D maybe of the wgeneral type of Patent No. 815,321, granted Marchj13, 1906,

toKeith, Erickson and Erickson. Theside .switch and private magnet are omitted',however, and the circuits are,rnod1fied.1n.a ccordance. with the two wire system. of controlr The firstselector switchD may have access to other selector. switches si nilar to the switch D. As herein shown, howeveipflthe selector D. has access to trunk lines extending .to connector switches, oneotthetrunk lines extending to, the connector switch EL, The

connector E, maybe of the general typeof connector switch disclo sed'in-U. S; Letters PatentNo.,8l5,l76, granted March l13,1/1906,

switch private rnagn'et are omitted and the clrcults are modlfiedtinaccordance wlth the iZWO WllG system of control. Therot-ary connectonE mayghavemccess togroups of trunkl nes extend ng tOpllVtLliQbIZLllCll exchanges, .also, itfl nay,be stated that each maybe divided into any convenient number of trunk lines from one to ,ten in each group. Each contact set comprises four contacts, which are the usual line, private or. test con-p ,tacts,,and an extratest contact. This extra test contact is dead except in the case of the contact setstwhich are, associated/with the first and lastitrunk linesof atgroup. The

two test contacts, associated with the last trunk line of each group being connected together and the first extra test contact associated with each group being connected to a normally open contact, which is controlled by the bridge cut-off relay, individual to the first trunk line of each group.

One of the trunk lines accessible to the connector E is the trunk line 96 and 99, which is assumed to be the first trunk line in some particular group. Each of the trunk lines in this group are two'way trunk lines. Thatis, the operator at the branch exchange may extend a connection to the main exchange, through the medium of an individual trunking switch, which may be similar to the switch 0. .I have only shown the bridge cut-oft relay of the trunking the branch exchanges. Associated with the connector E, I have shown a ringing equipment H, and a busy signalling machine I. This apparatus may be the usual type, such as is found in well known telephone systems. V

' Having briefly described the apparatus in volved, I will now proceed to explain more in detail the operationof the same.

l/Vhen the subscriber at sub-station A re moves his receiver, a circuit isvclosed at the switch-hook springs for the line relay 20 of the switch C in series withthe line circuit.

' Relay 20 upon energizing, closes a circuit at springs 21, including switching relay 22, and rotary magnet 23 in series, and at the same time at springs 24 for the magnet 23 to the private wiper 27; Suppose that the trunk line upon which the switch C is resting is busy; then a ground potential 1s present on the private contact corresponding to this trunk; this ground potential will short the high resistance relay 22 and energize the rotary magnet 28 to step the wipers 26,2? and 28 to the contacts of the next trunk line. If this trunk line is busy, the rotarymagnet will again be energized and this operation will continue until an idle trunk is reached, atwhich time there will be no potential present at the contact which the private wiper 2Tmeets. 'Relay 22 will no longer be shorted out and will immediately energize over the series circuit hereinbefore traced, to extend the l ne of sub-station A to atrunk line leadlng to a selector switch;

energized. responding to the first digit of the called switch D. Relay 22 upon energizing closes a circuit for the line relay 34 of switch D in series with the linecircuit and wipers 26 and 28. Relay 34 upon energizing, closes a circuit at springs 35 and 36 for slow release relay 88. Relay 38 energizes to prepare a circuit at springs 39 and 40 for slow relay 42 and vertical magnet 43 in series, opens a point at springs 40 and 41 in the circuit of release magnet 44, and closes] a circuit at springs 45 to hold the relay 22 of switch C When a series of impulses cornumber are delivered by the calling device atsub-station A, the relay 34 operates to open and closethe circuit of the vertical magnet 43 at springs 36 and 37, a corresponding number of times, to thereby step thewipers 5'1, 52 and 53 to a desired level of bank contacts; "Relay 42 is energized in series with magnet 43, and operates to close a circuit at springs 47 and 48 for the rotary interruptor relay 49. IIelay 49 energizes to prepare a circuit for the rotary magnet 50 at springs 55, and close a locking circuit for itself, through springs 54. As soon as relay -42 de-energizes after the impulses cease, a circuit for the rotary magnet is closed at? springs 46 and 48. The magnet 50, therefore, operates to rotate the wipers 51, 52 and 53 onto the first contact of the elected'level and opens the locking circuit of relay 49 at springs 56. Ixelay 49 thende-energizes and opens the circuit of magnet50 at springs 55, which magnet de-energizes and prepares a new circuit for relay 49 to the private wiper 52, If the first trunk is busy, the relay 49 will again be energized by the guarding potential at the contact associated with wiper 52 to againclose the circuit of mag net 50. The rotary magnet again operates to step the wipers to the next trunk line. When the first idle trunk is reached, no potential is present at wiper 52, andrelay 57 which has heretofore been short-circuited, is energized in series with relay 49 from ground potential at springs 45. Re

lay 49 being of lower resistance than 57 does.

not energize at thisltime. Relay 57 upon energizmg, prepares a locking circuit for 1tself at springs 58,which will be completed over wiper 52 from. the next succeeding switch, also by means of springs 60 and 61, extends the line circuit to a trunk line leading to a connector switch.

Suppose the first idletrunk line is the trunk line 62, 63 and 64 leading to the rotary connector switch E. Then a circuit for line relay is completedas follows: from ground through lower winding of relay 70, springs 71 and 74,0onductor 64, wiper 58, springs 61, conductor 31 wiper 28, to and through sub-station A, wiper' 26, conductor 29, springs 60,.wiperfl5'l, conductor 62,

springs 77 and 75, upper windiiigof relay to battery. Relay 70upon energizing,

closes a circuit for slow releaserelay 79."

Relay 7 9 upon energizing, places ground potential through springs 80 to the release trunk to render the switch E busy to other calls andto hold relays22 and 57 of switches C and D respectively, energized,"

opens a point in the circuit of release magnet 81 at springs 83 and 82 and prepares a circuit for relay 85 and vertical magnet8'6 in series at springs 83 and 84.

Assume that the subscriber at sub-station called number is transmitted by the calling device, the line relay 7 0 operates to open and close the circuit of magnet 86 at springs 101.

The circuit of the vertical magnet 86exten'ds from ground through springs 101, springs 83 and 84, springs 102 and 103, slow relay 85 and vertical magnet to battery. The

vertical magnet will be operated a number of times to stepthe wipers 88, 89, 90 and 91 to the group or level of trunk lines in which terminals of the desiredline are located. Upon the first vertical step of the wipers, the off normal springs 102 and 103 are opened and spring102 comes into contact with spring 104. Although the circuitfor the vertical magnet is openedflby springs 102 and 103, a new circuit has been closed by the operation of relay 85, which circuit extends from ground through springs 101, springs 83 and 84, springs 102 and 104, springs 106 and 105, and over the previously traced circuitthrough the vertical magnet. Belay 85 remains energized during the series of impulses to the vertical magnet and upon de-energizing after the impulses cease, prepares a circuit for slow relay 108 and the 5 rotary magnet 109 in series.

Now, when the line relay v'70 is again operated in response to the third or last digit of the called number, the rotary magnet is operated to rotate the wipers 88, 89, 90 and 91 to the terminals of the first line in the desired group. The circuit of the rotary magnet extends from ground through springs 101, springs 83 and 84, springs 102 and 104, springs 106 and 107, slow relay 108, springs 110, springs 111 and rotary magnet 109 to battery. Relay 108-energizes upon the first rotary impulse and retains its armature dur ing the series of impulses to the rotary magnet 109, and at springs 112 and 113 closes a circuit for relay 115. Relay 115 uponenergizing, prepares a circuit at springs 120 for the lower winding of relay 119 andwinding of relay 118' in series, also closes a locking circuit for itself at'spring's1'17. Relay108 upon de-energizing, afterthe impulses to the rotary magnet cease, closes the circuit for lower windmg of relay 119 andwmdingof relay118in series, but withouteffect'at this time. Relay 118 is adjusted stiff and the springs 125 and 126 are to make contact be fore springs 127 close. If the first trunk line in the group is busy the private contact 98 will be grounded and'a circuit for relay118 will be closed fromground at contact 98, wiper 90 in engagement therewith, springs 116, springs 121 and 122, springs 124, winding of relay 118 to battery. Relay 118 now energizes, closes a lockingcircuit foritself at contact 126, and at contact 127 closes a circuit for the rotary magnet 109-as follows: from ground at springs 80, through springs 130 and 128, springs 113 and 114, springs 127, springs 110,springs 111 and through magnet 109 to battery. Therotary magnet now operates to step the wipers 88, 89, etc., to the contacts associated'withthe next trunk line and at springs 124 opens the circuit of interruptor relay 118; whereupon relay 118 falls back and breaks the circuit of the rotary magnet. On the deenergization of the rotary magnet, if the contactengaged by the private wiper 90 is grounded, relay 118 will again be energized and the rotary magnet will then operate to step the wiper to the next succeeding contact. This operation-will continue until the last trunk in the group is reached and if that trunk line is busy, a ground potential will be present on both test contacts associated with that trunk, since the last two test contacts of any group of trunks are connected together as hereinbefore stated. Therefore a circuit will be completed for busy relay 132 from ground at the contact associated with Wiper 89 through springs 125, springs 133 and'134 and through relay 132 to battery. Relay 132 upon energizing, closes a locking circuit for itself at springs 134 and 135, opens a point in the circuit of rotary magnet 109 at springs 110, and connects the secondary winding of busy machine I with the lower talking conductor, thereby giving the subscriber at sub-station A, a busysign'al.

If all the trunks in the elected group had been busy just prior to the last series of impulses delivered. by the calling device, then a ground potential would have been present at the first extra test contact 97. Under these circumstances, since the bridge cut-off relay of each trunk is energized, a circuit may be traced from ground at bridge cut-off relay springs 140 associated with the last trunk line in the group, springs 141, springs 142, test contact 97 and over the previously traced circuit, through the busy relay 132 to battery. Current flow over the abovecircuit energizes relay 132, thereby giving the subscriber a busy signal and avoiding unnecessary rotation of the connector switch E.

When the callingsubscriber replaces his receiver, the circuit of line relay 7 0 is opened at the springs operated by the receiver hook. Relay 70 de-energizing, opens the circuit of relay 7 9 and closes a point in the circuit of release magnet 81 at springs 101. When relay 79 de-energizes it closes the circuit of the release magnet 81 at springs 82 and 83, also removes ground potential from the release trunk at springs 80, which opens the holding circuit of relays 22 and 57 of switches C and D respectively. Relay 57 of switchD upon de-energizing', closes a circuit for the release magnet 44. magnets 44 and 81 of switches D and E respectively, restores the wipers to normal position in the well known manner.

Now when this rotary connector is seized by'a toll operator over the trunk conductors 65 and 67, the line relay 7 O is energized through the windings of differentially wound relay 143. The relay 143 does .not energize at this time, as its two windings oppose each other. The connector switch E is operated through the medium of its line relay 7 O in the same manner as hereinbefore described, to bring the wipers 88, 89, 90 and 91 into engagement with the first set of contacts associated with the selected group of trunk lines; assuming that wiper 89 is now in engagement with contact 97 and all the trunks in that group are busy, a'circuit for busy relay 132 is completed as hereinbefore traced. Relay 132 upon energizing at this time closes a shunt or short circuit about the lower winding of slow relay 143 at springs 144, connects the secondary winding of the busy machine I with the lower talking conductor, opens a point in the circuit of rotary magnet 109, at springs 110 and closes a holding circuit for itself at springs 134 and 135.

The short-circuit which is thus established about the lower winding of relay 143 causes said relay whose windings are diiferentlal, to be energized, thereby switching the looking circuit of the busy relay 132 to the wiper 89. This new circuit extends from ground at wiper 89, springs 125, springs 144' and 145, springs 135 and 134, and relay 132 to battery. It will be seen, therefore, that relay 132 instead of being permanently locked, remains energized only as long as all of the trunk lines in the group arebusy, and until ground is removed from the private contact 97.

Supposing that the second trunk now becomes idle, springs 141 will be separated and ground will be removed from contact 97; therefore relay 132 will deenergize and restore its springs to normal and at springs 110 closes a circuit for rotary magnet 109, as previously traced, which will operate to step the wipers onto the next set of contacts associated with the second trunk. Therefore as soon as wiper 90 comes into engagement with the idle contact associated The energization of with the second trunk line. a circuit for lower winding of relay 119 is completed over, the following path: from ground through springs 80, springs 130 and 128, springs 113 and 114, springs 146 and 144, springs 135 and 136, springs 120,l0wer winding of relay 119, springs 121 and 122, springs 116, wiper 90 and through the bridge cut-off relay associated with the sec- 0nd trunk line to battery, Relay 119 is now energized and closes a locking circuit for Relay 149 energizes and operates the springs.

'72 and 76 and the associated contacts to reverse the connections. of the line relay 7 0 to the calling line' and to short-circuit the windings of relay 143.

The release of the connector E after conversation has taken place, is controlled in the same manner as that previously described, when a connection was established by the subscriber at sub station A. It will be seen therefore, that I have provided a very useful and efficient method by which an operator after establishing a connection to a group of trunks extending to a branch exchange which are all in'use, will be automatically connected to the first trunk line to become idle.

Having fully described and ascertained my invention in the foregoing specification, what I claim to be new and desire to have protected by Letters Patent will be pointed out in the appendedclaims.

lVhat I claim as my invention is: 1. In a telephone system, a calling line, an automatic switch, a group of trunk lines accessible to said switch, means for operating said switch for causing it to automati-. I

net-to antqmatieal yien ra ewto;select trunk n on o z a wsronps, meansipr i l the automatic operatlon of any of said the trunks in the electe dggrouprbecomesidle 'before said, switch is,released,and means for ,aga-in ,giving the busy isi'gnal should the idle .trunknagain become busy before the wipers ,joi said switch .gain (access thereto.

3. ,In a. telephone system, an automatic switch, a plurality of ,trunk lines accessible thereto gdiyided into groups and sub-groups, means for operating -said switch to select esu eemnp o .trunk ,mea sicont oll r v,eithergoi two gdiiierent ,paths for ,GfiUSlIIg said ,szwitch rto automatically. (rotate over the trunk inssaidisn sn pi in ear f l vidle @1 me ns i ir s-even ng the rotation of s id witch when n 1 h it unksin h ubgroup Li ie -busy,. and means effective when the switch -is,controlled ,QOYBI' one path for permitting the automatic rotation of said switch when-nnyaone-ofthe trunks in said sub- ;group becomes (idle and don preventing furthenoperation ofthe switchzwhen the same is controlled over the other path.

4. :In a telephone ,system, ,a -,trunk selectling ,switch {accessible viaatwo paths, 1 a plurality of lines aeeessible thereto divided into-groups, agtest, contact rforreach group,

. agtest wiper for g-the switch nieans for operating. saidsswitchto,mo-ve sa d test ,wiper into engagement with thetesticontact of a group, means formaking said group of trunks busy, 7 1 ,115 li er pr v nting itur h r operation of said switch if all the trunks in the ,group are busywhen the wiper meets the test contact of the group, means for permitting further operation of the switch when one of the trunk lines in the group becomes idle if said switch has been seized over one path and means for preventing further operation of the switch when one of the trunk lines in the group becomes idle if the switch has been seized over another path.

5. In a telephone system, an automatic switch, groups of trunk lines accessible to said switch, means for operating said switch over one path in response to digits of a called number for causing it to automatically operate to select a trunk in one of said groups, means for preventing the automatic operation of said switch and for operating a busy signal when all of the trunks in the selected group are busy, means for preventing any further operation over said path; said switch operated over other paths in response to digits of a called number, means controlled over said other paths for preventing the automatic operation of said switch when all of the trunks in the selected group are busy, and means for causing said switch towautomatically operate when any one of thetrunks in theseleotedgroup become idle before the switch is released.

6.111 a telephone system an automatic switch, groups of trunk lines accessiblethereto,.,means,"Eor seizing said switch via more thanone pathand for operating the ,switch toncause it-to automaticallyaselect an idlettrunkline inoneoi saidgroups, means ,operated when all of thetrunks in the group i are busy for giving a busy signal to the calling subscriber ,and for. preventing the operation of said automatic selecting means, and means operableonly when the switch is seiaedvi'a one ofisaid pathsafor permitting the operation of said automatic selecting means whenever a trunk line in thegroup becomes idle.

;7. In a telephone system, calling lines, an automatic switch, a group of trunk lines ,accessibleto said switch, said switch having .an automatic selecting operation to seizeidle ,tru-nks, means in saidswitch when operated over one of said calling lines for transmitting a busy signal to the calling line when all ythetrunks arebusy and for preventing any automaticaselecting operation of said switch, andimeanslin said switch efii'ectiveiwhen said switchisoperated overanother of saidilines for transmitting abusy signal thereto when all the trunks are busy previous tovor after the automatic selecting operation of the i switchp Shin a telephone system, an automatic switch, said switch accessible to groups of Vtrunkflines, a busysignalingdevice in said switch, said deviceoperable only one time when ,said switch is seized in one manner {and operable a plurality ,of times when seized in another ,man-ner.

9. In a telephone system, an automatic switch having a relay therein, a group of trunks accessible to said switch, means controllable via two paths for operating said switch and for causing it to automatically rotate over said group in search of an idle trunk line, said relay being included in one of said paths only, means for preventing said switch from automatically rotating if all of said trunks are busy and for giving the calling party a busy signal, and means controlled by said relay when said switch is operated over the associated path for thereafter allowing the automatic rotation of said switch when one of said trunks become idle.

10. In a telephone system, an automatic switch, a group of trunks accessible to said switch, means controllable via two paths for operating said switch and for causing it to automatically rotate over said group in search of an idle trunk line, means for preventing said switch from automatically rotatin r if all of said trunks are busy and for giving the calhng party a busy signal,

and a relay in said switch for determining whether or not automatic rotation will be permitted after a busy.

11. In a telephone system, an automatic switch, a group of trunk lines accessible to said switch, a trunk line incoming to said switch and having two branches over either of which said switch may be taken for use, trunk hunting mechanism in said switch, means for preventing the operation of said mechanism in case all the trunks in said group are busy, and means effective only in case said switch is taken for use via a particular one of said branches for automatically initiating the operation of said mechanism if a trunk line in said group becomes idle before the switch is released.

12. In a telephone system, a group of trunk lines, an automatic switch for use either by an operator or a calling subscriber, trunk hunting mechanism in said switch, means for preventing the operation of said mechanism in case all the trunks in said group are busy, and means effective only in case said switch is in use by an operator for automatically initiating the operation of said mechanism if one of said trunk lines becomes idle before the switch is released.

13. In a telephone system, groups of trunk lines, a rotary connector, means controllable either by an operator or a calling subscriber for operating said connector to select a group of said trunk lines, automatic mechanism for causing said connector to select an idle'trunk in a selected group, means for preventing the operatic-n of said mechanism in case all the trunks in the selected group are, busy, and means effective only in case said connector is in use by an operator for automatically initiating the operation of said mechanism in case a trunk in the selected group becomes idle before the connector is released.

' 14. In a connector switch, a line relay, a differential relay in series'with said line relay, a test relay, and'contacts controlled by said test relay for shunting one winding of said diflerential relay.

15. In a connector switch,a test relay, a test wiper, an initial energizing circuit for said relay including said wiper, a locking circuit'for said relay excluding said wiper, a second locking circuit for said relay including said wiper, and a differential relay for determining which of said locking circuits is to be efi ective.

16. In a connector switch, a test relay, a

test wiper, an initial energizing circuit for said relay including said wiper, a locking circuit for said relay excluding said Wiper, a second locking circuit for said relay including said wiper, a line relay, and a relay in series with said line relay for determin- I ing which of said locking circuits is to be effective.

17. In a connector switch, a test relay, a test wiper, aninitial energizing circuit for said relay including said wiper, a locking circuit for said relay excluding said wiper,

a second locking circuit for said relay including said wiper, two incoming lines terminating in said connector for alternative use in connecting therewith, and arelay in cluded in only one of said lines for rendering one looking circuit effective and the other ineflective.

Signed by me at Chicago, Cook County, Illinois, this 28th day of August, 1918.

VEMIL JAcoBsEN 

